Author: John Mulindi
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How Cascade Control System Enhances Dynamic Response to Load Changes
The major limitation of a conventional feedback control system is that the correction for disturbances does not start until the process output deviates from the setpoint. Feedforward control provides big improvements in processes with large time constraints or time delays. … Read more
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Cable Screens: Types & Connections
Electromagnetic Compatibility (EMC) is one of the key factors of consideration in the design, construction, manufacture and installation of electrical and electronic equipment and systems. Electrical equipment must be designed not only to meet a functional technical performance specification but … Read more
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AC to AC Power Converters with Intermediate DC Link: Types, Features & Applications
This category of AC drives that is often referred to as “Variable Frequency Inverters” is one of the most extensively used drives in industrial motor control applications. Generally, the concept of these inverter drives can be summarized into three parts:… Read more
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Instrumentation Systems Installation: Precautions to Take
Analog systems are normally based on low voltages and as a result, they are vulnerable to electrical noise. In most plants, a PLC may be controlling 415 V high power motors at 100 A, and at the same time, … Read more
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Vacuum Circuit Breakers: Features, Operation & Applications
In vacuum circuit breakers, vacuum typically at pressures ranging from 10-9 to 10-6 bar is used as the quenching medium. At such pressures, high dielectric strength can be achieved. The contact separation needed at such low pressures is … Read more
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DC to DC Power Converters: Function, Types, Operation & Applications
DC to DC power converters also referred to as choppers provide the means to change one DC voltage to another. Normally the conversion is to a lower voltage however, we also have step-up converters. DC to DC power converters are … Read more
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Basic Facts about 4-20 mA current loop in Process Instrumentation
The 4-20 mA current loop, like the one shown in the diagram below is a typical way of transmitting sensor information in most of industrial process monitoring applications. Figure 1.0: typical components used in a loop powered application. A sensor… Read more
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What are Supercapacitors?
Supercapacitors (double-layer or ultracapacitors) are devices that store extremely large amounts of charge (from 0.022 F to 55 F) much more than a normal capacitor. Their level of energy storage approaches around 1/10 that of a low-density battery. But, … Read more
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Digital Voltmeters: Basic Features, Operation & Applications
The digital voltmeter (DVM) displays measurement of ac or dc voltages as discrete numbers instead of a pointer deflection on a continuous scale as in analog instruments. A digital voltmeter basically consists of an analog-to-digital converter, a set of seven-segment … Read more
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Equipment Grounding vs. System Grounding
Grounding or earthing an electrical system is the process of connecting all metalwork/frame of electrical equipment i.e. the non-current carrying part or some electrical component of the system such as the neutral point in a star-connected system, one conductor of … Read more